允许我们将文件和目录作为实体进行操作的最重要的包是os包。
io包具有读取数据并将其从源传输到字节流的io.Reader接口。io.Writer接口从提供的字节流中读取数据，并将其作为输出写入目标资源。
创建一个空文件
package main
import (
"log"
"os"
)
func main() {
emptyFile, err := os.Create("empty.txt")
if err != nil {
log.Fatal(err)
}
log.Println(emptyFile)
emptyFile.Close()
}输出
2018/08/11 15:46:04 &{0xc042060780}创建目录
package main
import (
"log"
"os"
)
func main() {
_, err := os.Stat("test")
if os.IsNotExist(err) {
errDir := os.MkdirAll("test", 0755)
if errDir != nil {
log.Fatal(err)
}
}
}重命名文件
package main
import (
"log"
"os"
)
func main() {
oldName := "test.txt"
newName := "testing.txt"
err := os.Rename(oldName, newName)
if err != nil {
log.Fatal(err)
}
}将文件从一个位置移动到另一个位置
os.Rename()还可以将文件从一个位置移动到另一个位置，同时重命名文件名。
package main
import (
"log"
"os"
)
func main() {
oldLocation := "/var/www/html/test.txt"
newLocation := "/var/www/html/src/test.txt"
err := os.Rename(oldLocation, newLocation)
if err != nil {
log.Fatal(err)
}
}复制文件
package main
import (
"io"
"log"
"os"
)
func main() {
sourceFile, err := os.Open("/var/www/html/src/test.txt")
if err != nil {
log.Fatal(err)
}
defer sourceFile.Close()
// Create new file
newFile, err := os.Create("/var/www/html/test.txt")
if err != nil {
log.Fatal(err)
}
defer newFile.Close()
bytesCopied, err := io.Copy(newFile, sourceFile)
if err != nil {
log.Fatal(err)
}
log.Printf("Copied %d bytes.", bytesCopied)
}输出
2018/08/15 03:43:39 Copied 100 bytes.获取文件的元数据
package main
import (
"fmt"
"log"
"os"
)
func main() {
fileStat, err := os.Stat("test.txt")
if err != nil {
log.Fatal(err)
}
fmt.Println("File Name:", fileStat.Name()) // Base name of the file
fmt.Println("Size:", fileStat.Size()) // Length in bytes for regular files
fmt.Println("Permissions:", fileStat.Mode()) // File mode bits
fmt.Println("Last Modified:", fileStat.ModTime()) // Last modification time
fmt.Println("Is Directory: ", fileStat.IsDir()) // Abbreviation for Mode().IsDir()
}输出
File Name: test.txt
Size: 100
Permissions: -rw-rw-rw-
Last Modified: 2018-08-11 20:19:14.2671925 +0530 IST
Is Directory: false删除文件
package main
import (
"log"
"os"
)
func main() {
err := os.Remove("/var/www/html/test.txt")
if err != nil {
log.Fatal(err)
}
}逐个字符读取文本文件
package main
import (
"bufio"
"fmt"
"os"
"strings"
)
func main() {
filename := "test.txt"
filebuffer, err := os.ReadFile(filename)
if err != nil {
fmt.Println(err)
os.Exit(1)
}
inputdata := string(filebuffer)
data := bufio.NewScanner(strings.NewReader(inputdata))
data.Split(bufio.ScanRunes)
for data.Scan() {
fmt.Print(data.Text())
}
}截断文件内容
操作系统。Truncate()函数会将文件内容减少到第二个参数中传递的 N 个字节。在下面的示例中，如果 test.txt 文件的大小大于 1Kb，那么它将截断剩余的内容。
package main
import (
"log"
"os"
)
func main() {
err := os.Truncate("test.txt", 1000)
if err != nil {
log.Fatal(err)
}
}在文本文件中追加内容
package main
import (
"fmt"
"os"
)
func main() {
message := "Add this content at end"
filename := "test.txt"
f, err := os.OpenFile(filename, os.O_RDWR|os.O_APPEND|os.O_CREATE, 0660)
if err != nil {
fmt.Println(err)
os.Exit(-1)
}
defer f.Close()
fmt.Fprintf(f, "%s\n", message)
}更改文件权限、所有权和时间戳
package main
import (
"log"
"os"
"time"
)
func main() {
_, err := os.Stat("test.txt")
if err != nil {
if os.IsNotExist(err) {
log.Fatal("File does not exist.")
}
}
log.Println("File exist.")
// 修改权限
err = os.Chmod("test.txt", 0777)
if err != nil {
log.Println(err)
}
// 修改所有权
err = os.Chown("test.txt", os.Getuid(), os.Getgid())
if err != nil {
log.Println(err)
}
// 修改时间
addOneDayFromNow := time.Now().Add(24 * time.Hour)
lastAccessTime := addOneDayFromNow
lastModifyTime := addOneDayFromNow
err = os.Chtimes("test.txt", lastAccessTime, lastModifyTime)
if err != nil {
log.Println(err)
}
}将多个文件压缩为ZIP文件
package main
import (
"archive/zip"
"fmt"
"io"
"log"
"os"
)
func appendFiles(filename string, zipw *zip.Writer) error {
file, err := os.Open(filename)
if err != nil {
return fmt.Errorf("Failed to open %s: %s", filename, err)
}
defer file.Close()
wr, err := zipw.Create(filename)
if err != nil {
msg := "Failed to create entry for %s in zip file: %s"
return fmt.Errorf(msg, filename, err)
}
if _, err := io.Copy(wr, file); err != nil {
return fmt.Errorf("Failed to write %s to zip: %s", filename, err)
}
return nil
}
func main() {
flags := os.O_WRONLY | os.O_CREATE | os.O_TRUNC
file, err := os.OpenFile("test.zip", flags, 0644)
if err != nil {
log.Fatalf("Failed to open zip for writing: %s", err)
}
defer file.Close()
var files = []string{"test1.txt", "test2.txt", "test3.txt"}
zipw := zip.NewWriter(file)
defer zipw.Close()
for _, filename := range files {
if err := appendFiles(filename, zipw); err != nil {
log.Fatalf("Failed to add file %s to zip: %s", filename, err)
}
}
}读取ZIP文件内的文件列表
package main
import (
"archive/zip"
"fmt"
"log"
"os"
)
func listFiles(file *zip.File) error {
fileread, err := file.Open()
if err != nil {
msg := "Failed to open zip %s for reading: %s"
return fmt.Errorf(msg, file.Name, err)
}
defer fileread.Close()
fmt.Fprintf(os.Stdout, "%s:", file.Name)
if err != nil {
msg := "Failed to read zip %s for reading: %s"
return fmt.Errorf(msg, file.Name, err)
}
fmt.Println()
return nil
}
func main() {
read, err := zip.OpenReader("test.zip")
if err != nil {
msg := "Failed to open: %s"
log.Fatalf(msg, err)
}
defer read.Close()
for _, file := range read.File {
if err := listFiles(file); err != nil {
log.Fatalf("Failed to read %s from zip: %s", file.Name, err)
}
}
}提取或解压缩
package main
import (
"archive/zip"
"io"
"log"
"os"
"path/filepath"
)
func main() {
zipReader, _ := zip.OpenReader("test.zip")
for _, file := range zipReader.Reader.File {
zippedFile, err := file.Open()
if err != nil {
log.Fatal(err)
}
defer zippedFile.Close()
targetDir := "./"
extractedFilePath := filepath.Join(
targetDir,
file.Name,
)
if file.FileInfo().IsDir() {
log.Println("Directory Created:", extractedFilePath)
os.MkdirAll(extractedFilePath, file.Mode())
} else {
log.Println("File extracted:", file.Name)
outputFile, err := os.OpenFile(
extractedFilePath,
os.O_WRONLY|os.O_CREATE|os.O_TRUNC,
file.Mode(),
)
if err != nil {
log.Fatal(err)
}
defer outputFile.Close()
_, err = io.Copy(outputFile, zippedFile)
if err != nil {
log.Fatal(err)
}
}
}
}